Forests are an important resource, both as a source of wood for fuel, building and paper and as habitats for a variety of wildlife. Forestry practices in much of the developed world are almost sustainable - felled trees are replanted and the wildlife found in most commercial forests has been improved by the addition of other plants which make the forest resemble a more natural habitat.

Throughout much of the developing world however, forests are often not well managed and are threatened by agricultural expansion, commercial logging, forest fires and overgrazing. As well as the extinction of wildlife species, the loss of a forest an also lead to soil erosion. Such mismanagement, in the extreme, can lead to deforestation and the loss of an important natural resource. Trees utilise carbon dioxide during photosynthesis and can help "soak up" some of the excess carbon dioxide released into the atmosphere by mankind, that is causing global warming.

Sustainable forestry can be achieved by correctly managing forest resources through replanting, conservation and protection from fire, disease and pollution. Commercial forests should not be made up of only one tree species - there should be a variety of trees and a layer of smaller plants (an �understorey�) to provide refuges for wildlife.